It isn’t simply a case of forgetting some things and remembering others. Research shows that our brains are happy to make past events up

O
n the morning after the explosion of the space shuttle Challenger in January
1986, the ­psychologist Ulric Neisser distributed a short questionnaire to
his class at Emory University in Atlanta, asking students to describe where
they were, what they were doing and who they were with when they first heard
of the disaster. He collected the completed questionnaires and kept them for
three years. Then he contacted 44 of the participants and got them to do a
questionnaire just like the first. The aim was to test the accuracy of
so-called “flashbulb” memories of historic moments. The results were
startling. A quarter of the students misremembered every detail, yet some
were so sure their memories were correct that they insisted their previous
report, written the day after the disaster, must have been wrong.

As an example of popular-science writing Neisser’s account is pretty near
perfect, being at once a snatch